This invention generally relates to the imprinting and reading of sound data on a piece of printed sheet material, and is specifically concerned with the optical reading of an invisibly printed sound message on a greeting card.
Techniques for incorporating sound messages into greeting cards are known in the prior art. An example of such a device is disclosed in U.S. Pat. No. 5,063,698. Here, the user records a message into a telephone answering machine which the vendor of the card then encodes into a small, battery operated playback device installed in the card. When the card is opened, a switch may be depressed to activate playback of the sound message. A similar recording and playback device for use in a postcard is disclosed in U.S. Pat. No. 4,791,741.
While such prior art techniques certainly enhance the personalization of a greeting card or postcard, they are accompanied by a number of drawbacks. First, despite ongoing progress in the miniaturization of electronic components, such playback devices are relatively large and bulky relative to the sheet material that forms the card, and hence interfere with the aesthetics of the card by providing either an unsightly bulge or unwanted thickness along at least a portion of the card. To minimize the aesthetic intrusiveness of such modules, they are manufactured in as compact and lightweight a form as possible. However, the resulting small and lightweight structures of such modules necessarily limits the quality of the sound they produce, and renders them fragile and susceptible to breakage when conveyed through the various machinery of the postal service. Thirdly, the power cells used in such modules are likewise necessarily small and of limited power capacity, which in turn limits the module to a relatively short lifetime of operation.
It is also known to provide sound data on other forms of written or image bearing sheet material which is optically read by a hand-held device. For example, U.S. Pat. No. 3,970,803 discloses a system where a sound track is formed from a series of visible segments is printed over selected portions on the pages of a publication, such as a book. An optical scanner is provided which, when slid over the sound tracks, converts the sound track to sound. Similarly, French patent 2,494,873 discloses the use of a visibly printed bar code onto sheet music. A so hand-held stylus-like decoder reads the bar code when swiped over it in order to produce sounds representative of the musical notes on the sheet music.
However, in both of these inventions, the conspicuous visibility of the printed sound track or bar code is not only unsightly, but visually distracting which is particularly problematical in the sheet music disclosed in the French ""873 patent. While invisible inks are known, the necessary scanning motions that the system operator must execute in order to read the sound track or bar code necessitates that the printed representation of the sound data in these inventions be easily seen for proper alignment between the scanner and track or code. Finally, because of the required alignment between the sound track or bar code and the head of the scanning mechanism during the scanning movement, there is a possibility that the sound reproduction in either of these two prior art systems may be either unreliable or distorted due to inaccurate alignment.
It is also known to adhere a magnetic recording strip onto a photographic print for the storage of a sound message or commentary directly on the print. Such a system is disclosed in U.S. Pat. No. 4,270,853. However, such a system provides limited storage space and uses up available image space when placed on front of the print. Moving the magnetic strip to the back of the photographic print reduces its accessibility and makes it awkward to reproduce the sound while viewing the print. Moreover, this system requires a magnetic reader head that must be swiped along the longitudinal axis of the magnetic strip in accurate alignment therewith for the sound message to be played back with any degree or reliability and accuracy.
Clearly, there is a need for a technique for providing a personalized sound message on a greeting card, postcard, or other written message which does not rely upon electronic modules that create unwanted thicknesses in the card sheet material or unsightly bar codes or magnetic strips. Ideally, such a system would be capable of incorporating a high-quality sound recording directly on the surface of the card in an easy, inexpensive and visually unintrusive manner. The available message length should be as long as possible to accommodate sound messages of long duration. Finally, the system should allow for the playback of such a sound message in an easy and reliable manner which does not rely upon sweeping or scanning movements that must be critically aligned with a bar code or magnetic strip.
Generally speaking, the invention is a system and method for optically imprinting and reading sound data from a printed piece of sheet material, such as a greeting card that overcomes the shortcomings associated with the prior art. The system comprises an encoding device for converting a sound message into a two-dimensional encodement, a printer for invisibly imprinting the encodement onto a piece of sheet material, and a reader including an image sensor array for optically and remotely reading the encodement and converting it into sound corresponding to the message without the need for a swiping or scanning movement.
The encodement may be printed directly onto the printed sheet material, or onto a different, transparent sheet of material that is adhered or otherwise secured onto the printed sheet material. Where the piece of sheet material includes an imprinted image or design, the encodement may be invisibly integrated into such image or design. Such invisible integration allows the use of infrared dyes that would be faintly perceptible if printed against a blank, light background while still preventing the encodement from becoming a visual distraction on the greeting card or postcard that the system or method is applied to.
The encoding device preferably includes a digitizer for converting an analog sound system into digital data, a compressor circuit for compressing the digital sound data, and a circuit for rendering the compressed digital sound data into a two-dimensional encodement. The printer preferably imprints the two-dimensional encodement onto the piece of sheet material in a manner that is invisible to the human eye. The printer can either print the encodement onto the piece of printed sheet material, or onto another piece of sheet material (which may be transparent) which is subsequently secured onto the printed material. The reader may include a lens for focusing an image of the encodement onto the image sensor array to allow it to be remotely read. The image sensor array may be either a two-dimensional array or a combination of a linear array and a movable mirror which sweeps the focused encodement image across the array in such a manner as to obviate the need for a sweeping movement of the reader. The reader may also include a decompression circuit for converting digital data received by the image sensor into an analog sound signal representative of the original sound message, as well as a speaker for converting the analog sound signal back into sound.
The method of the invention includes the steps of recording a sound message, converting the sound message into a two-dimensional compressed encodement, invisibly imprinting the encodement onto a greeting card or a postcard or other written message, and then optically reading the encodement from the greeting card by focusing an image of the encodement onto an image sensor array. The image sensor array responds to the focused image by generating a compressed digital sound signal which is decompressed into an analog sound signal and converted into sound representative of the sound message.
The message recordation step may be implemented by remotely transmitting a sound message through any remote voice communication system, such as a telephone, radio, or internet. The message recorded may originate from a microphone, another recording device such as a tape recorder, or the sound recording of a camera having such a capacity, an audio CD or CD-ROM, or even a remote sound library. The method of the invention may further include the step of augmenting and editing the sound message prior to the conversion of an analog sound signal representative of the sound message into a compressed digital signal. The addition of such a step finds particular utility in a greeting card customizing kiosk, where the user might wish to mix sounds (such as background music) with a verbal message that is imprinted onto the greeting card or other type of communication.